Few-Layered PtS2 Phototransistor on h-BN with High Gain

5 years ago

Few-Layered PtS2 Phototransistor on h-BN with High Gain

Huiqiao Li, Weike Wang, Tianyou Zhai, Mingliang Tian, Yang Chai, Liang Li

The very recently rediscovered group-10 transition metal dichalcogenides (TMDs) such as PtS2 and PtSe2, have joined the 2D material family as potentially promising candidates for electronic and optoeletronic applications due to their theoretically high carrier mobility, widely tunable bandgap, and ultrastability. Here, the first exploration of optoelectronic application based on few-layered PtS2 using h-BN as substrate is presented. The phototransistor exhibits high responsivity up to 1.56 × 103 A W−1 and detectivity of 2.9 × 1011 Jones. Additionally, an ultrahigh photogain ≈2 × 106 is obtained at a gate voltage Vg = 30 V, one of the highest gain among 2D photodetectors, which is attributed to the existence of trap states. More interestingly, the few-layered PtS2 phototransistor shows a back gate modulated photocurrent generation mechanism, that is, from the photoconductive effect dominant to photogating effect dominant via tuning the gate voltage from the OFF state to the ON state. Such good properties combined with gate-controlled photoresponse of PtS2 make it a competitive candidate for future 2D optoelectronic applications. A few-layered PtS2 phototransistor on h-BN with high gain is demonstrated. High responsivity up to 1.56 × 103 A W−1 and detectivity of 2.9 × 1011 Jones at a gate voltage Vg = 0 V are achieved. Moreover, the photocurrent generation mechanism can be tuned with the back gate from photoconductive effect dominant in the OFF state to photogating effect dominant in the ON state.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201701011